There are many types of hazards today which can cause serious injury or even death. These hazards include radiation, corrosive or toxic chemicals, infectious biological agents, metal projectiles, such as bullets or shrapnel, and fire. While many of these hazards have been known for years, it has become more urgent and difficult to protect against them in light of recent terrorist activities, including the Sep. 11, 2001 terrorist attacks on the World Trade Center.
Many of the hazards faced today used to be thought of as localized to sites such as nuclear power plants, nuclear fuel processing plants, nuclear clean-up sites, x-ray scanners, chemical refineries and biological laboratories. Nonetheless, the growth of terrorism has extended these hazards to virtually any location. In the case of nuclear radiation, the detonation of a portable nuclear bomb, such as a “dirty bomb” incorporating nuclear waste material, could spread deadly radiation throughout a metropolitan area. Similarly, the release of infectious biological agents is no longer confined to biological research laboratories, but could occur anywhere that a terrorist chooses to release such infectious biological agents.
In addition to needing to protect against life threatening hazards over a much larger area, there is also a need to simultaneously protect against multiple types of hazards. For example, while one can obviously anticipate nuclear hazards at a nuclear power plant, the advent of terrorism means that it is now possible that deadly biological or chemical agents could be released at the same nuclear power plant. Similarly, while one tries to protect against the release of deadly biological agents at a biological research laboratory, the explosion by a terrorist of a “dirty bomb” near such a laboratory could introduce serious radiation hazards. For these reasons, it is no longer possible to provide effective protection by simply considering the most predicable types of hazards.
What is needed today is a way to effectively and economically provide protection against multiple types of hazards. In the past, for example, garments have been created to provide protection against a specific threat. In the case of radiation, there have been a number of previous attempts to mitigate the harmful effects of radiation through the creation of radiopaque protective garments. Typically, these radiopaque garments consisted of a stiff material, such as rubber, impregnated by lead or some other heavy metal which is capable of blocking radiation. Examples of lead impregnated radiopaque garments can be found in Holland's U.S. Pat. No. 3,052,799, Whittaker's U.S. Pat. No. 3,883,749, Leguillon's U.S. Pat. No. 3,045,121, Via's U.S. Pat. No. 3,569,713 and Still's U.S. Pat. No. 5,038,047. In other cases, radiopaque materials are incorporated into polymeric films, such as in Shah's U.S. Pat. No. 5,245,195 and Lagace's U.S. Pat. No. 6,153,666.
There have also been garments created to address the specific threat of metal projectiles, such as bullets or shrapnel. For example, Borgese's U.S. Pat. No. 4,989,266 and Stone's U.S. Pat. No. 5,331,683 disclose two types of bullet proof vests.
Additionally, fabrics have been developed to provide resistance to corrosive or toxic chemicals. Examples of such chemical protective fabrics can be found from a search of the internet. These chemical protective fabrics include polyethylene fabrics, such as DuPont's Tyvek®, polypropylene fabrics, such as Kimberly-Clark's Kleenguard® or Kappler's Proshield®, plastic laminate fabrics such as DuPont's TyChem® or Kimberly Clark's HazardGard I® and microporous-film based fabrics such as DuPont's NexGen® or Kappler's Proshield 2®. These chemical protective fabrics typically provide protection against biological agents also.
While these prior art fabrics, compounds and garments offer protection against the specific threats they are designed to address, they have a number of disadvantages. For example, while the lead filled prior art garments provide a good measure of protection against the harmful effects of radiation, these prior art garments are often heavy, stiff, expensive and bulky. As such, these garments are often uncomfortable, cumbersome and restrictive. Moreover, lead, of course, is a toxic substance which must be handled very carefully and cannot be carelessly disposed of. Also, there are sterilization and decontamination issues with these prior art radiation protective garments because they are typically too bulky, expensive and toxic to dispose of after each use.
Similarly, the bullet proof vests and bomb suits of the prior art tend to have poor heat dissipation properties. These bullet proof vests and bomb suits can be so uncomfortable to wear when it is hot that the user will choose to forego protection, rather than risk becoming overheated. This poor heat dissipation also has another disadvantage in military applications. When a soldier's body heat is allowed to build up inside a bullet proof vest or bomb suit, the soldier will have a high so-called “heat signature” in the other areas of the soldier's body where heat can be released. This uneven “heat signature” will allow that soldier to be easily located by an enemy's thermal imaging equipment. For the sake of survival in a high technology battlefield, it is better for the soldier to dissipate heat rapidly throughout his or her body and thereby have an even “heat signature.”
Moreover, it is quite likely that a garment designed to be effective against one hazard will be ineffective against other hazards. For example, the prior art radiation protective garments will probably not be effective in stopping bullets. Conversely, the prior art bullet proof vests and bomb suits will not be effective in stopping radiation.